Summary: Let $G$ be a finite group and $\chi $ be a character of $G$. We define the codegree of $\chi $ to be ${\rm codeg} (\chi ) = |G: {\rm ker}\chi |/ \chi (1)$. We study a few questions raised by Qian about character codegrees.
[6] Navarro, G.: Characters and Blocks of Finite Groups. London Mathematical Society Lecture Note Series 250. Cambridge University Press, Cambridge (1998). DOI 10.1017/CBO9780511526015 | MR 1632299 | Zbl 0903.20004